Before the bees are carried into the cellar it should be well aired and cleaned, and it will be well to keep it open for several days beforehand. No debris or refuse should be left in the cellar when the bees are taken in.
For zone 1 (fig. 1) it is usually desirable to wait until about the middle of November before putting the bees into winter quarters. If one could know exactly when the bees would have the last opportunity for a cleansing flight, they would be put into the cellar just after that, but we can not always be sure that there will be suitable weather for such flight in late November, and there is, therefore, considerable doubt every year as to just the right time to put the bees away. Frequently it happens that the weather is suitable for a flight about November 20, and it is best to wait until then before attempting to put the bees in the cellar. The flight of only a few bees from the hive should not be construed as a cleansing flight. In this connection it is highly desirable that the beekeeper keep a careful watch of the weather maps daily, so that he may know at all times about what weather may be expected for a few days in advance. For the beekeeper's purpose the daily forecasts published in newspapers are scarcely enough; and if no daily weather maps are convenient near by, it will repay the beekeeper well to subscribe for them. They are valuable not only at the time of putting the bees into the cellar but at many other times of the year.
Soon after a period when the barometric pressure has been low, bringing high temperatures suitable for flights (at least 60° F.), there usually will be a period when the barometric pressure is high, bringing lower, temperatures. At the shifting from low to high barometric pressure there is frequently a time when it is cloudy. This is a fine time to put the bees into the cellar. These periods of high and low barometric pressure follow each other with rather marked regularity in the fall, and it is rather safe to assume that just at the end of the well-defined low pressure which next follows after November 15 is the best time to put the bees into the cellar. It is better to put the bees in the cellar a week or so before the last opportunity for flight than to put them in after exposure to cold which is not followed by a cleansing flight.